Competition-quality crankshaft damper, made in the USA by BHJ. Used by race teams in the U.S. and Europe. Conventional in design, but contains BHJ's proprietary damping material inside. Made to light-interference-fit per our specification, drilled and tapped for a puller for easy removal. Timing marks machined into outer edge. Weight is 3.5 lbs., with the weight concentrated on the outer diamber due to its three spoke design. SFI-approved and serialized.